Artificial heart pump equipped with hydrodynamic bearing

Abstract

An artificial heart pump includes a casing ( 4, 15 ) having a blood inflow port ( 5 ) in its upper part, a blood outflow port ( 6 ) in its side surface part and a plurality of electromagnets ( 22 ) on its inner peripheral surface; a fixed shaft ( 17 ) projecting from the bottom surface of the casing and having thrust receptacles ( 18, 16 ) at its upper and lower end parts ( 12, 10 ), respectively; an impeller section ( 2 ) having a blood inflow section ( 3 ) in its center part and a blood outflow section ( 9 ) in its side surface part; an impeller support member ( 7 ) supporting the impeller section from below and having on its outer peripheral surface a plurality of permanent magnets ( 2 ) and in its center a hole part fitted on the fixed shaft to rotatably support the impeller section within the casing; a radial hydrodynamic bearing part formed between the inner peripheral surface of the hole part of the impeller support member and the outer peripheral surface of the fixed shaft; and thrust hydrodynamic bearings formed between the upper and lower end faces of the impeller support member and the thrust receptacles at the upper and lower end parts of the fixed shaft, respectively, whereby the impeller member is supported without contacting either the casing or the fixed shaft and rotates stably.

1 . An artificial heart pump comprising: 
 a casing ( 4 ,  15 ) having a blood inflow port ( 5 ) in an upper part, a blood outflow port ( 6 ) in a side source part and a plurality of electromagnets ( 22 ) on an inner peripheral surface;    a fixed shaft ( 17 ) projecting from a bottom surface of the casing and having thrust receptacles ( 18 ,  16 ) at upper and lower end parts ( 12 ,  10 ), respectively;    an impeller section ( 2 ) used inside the casing, having a blood inflow section ( 3 ) in a center part and a blood outflow section ( 9 ) in a side surface part, and comprising a plurality of impellers ( 1 );    an impeller support member ( 7 ) supporting the impeller section from below and having in a center a hole part fitted on the fixed shaft to rotatably support the impeller section;    a plurality of permanent magnets ( 21 ) provided on an outer peripheral surface of the impeller support member at positions facing the plurality of electromagnets ( 22 ) on the inner peripheral surface of the casing;    a radial hydrodynamic bearing formed between an inner peripheral surface of the hole part of the impeller support member and an outer peripheral surface of the fixed shaft; and    a thrust hydrodynamic bearing formed between upper and lower end faces of the impeller support member and the thrust receptacles at the upper and lower end parts of the fixed shaft.    
     
     
         2 . The artificial heart pump according to  claim 1 , wherein the impeller support member is provided with a plurality of thrust hydrodynamic pressure generation grooves ( 13 ,  11 ) at positions respectively facing the thrust receptacles ( 18 ,  16 ) at the upper and lower end parts ( 12 ,  10 ) of the fixed shaft, and the fixed shaft is provided a lower outer periphery with a plurality of radial hydrodynamic pressure generation grooves ( 20 ) to form a first thrust hydrodynamic bearing part, the radial hydrodynamic bearing and a second thrust hydrodynamic bearing part in this order.  
     
     
         3 . The artificial heart pump according to  claim 2 , wherein the thrust generation grooves ( 11 ) facing the thrust receptacle at the lower end part of the fixed shaft have a pump-in type spiral pattern to suck blood in from an outer peripheral side of the grooves and discharge the sucked blood to an inner peripheral side thereof, and the thrust generation grooves ( 13 ) facing the thrust receptacle at the upper end part have a pump-out type spiral pattern to suck blood in from an outer peripheral side of the grooves and discharge the sucked blood to an inner peripheral side thereof.